Method of and apparatus for working mineral materials and the like



Aug- 24, 1943- c. u. BURcH 2,327,496

METHOD 0F AND APPARATUS FOR WORKING MINERAL MATERIALS .ANDl THE LIKE Filed nec. 5, 1940' 4 sheets-sheet 1 N N mi W *s 4 E INVENTOR CHARLES J. BURCH BY S ATTORNEY Aug. 24, '1943. c. J. BURCH METHOD OF AND APPARATUS FOR WORKING MINERAL! MATERIALS AND THE LIKE Filed Dec. 5, 1940 4 Sheets-Sheet 2 INVENTR CHARLES J. BuRcH BY.

ATTORNEY llg.24, 1943. C, 1 BURCH 2,327,496

METHOD OF AND APPARATUS FOR WORKING MINERAL MATERIALS AND THE LIKE Filed Dec. 3, 1940 4 Sheets-Sheet 3 H R m RU A mA w NU Y A w vS R. Q A A/ mm m T H L CY .IIIL 1 D. B

|.1 IIIIJ.

lllll l I I I I l l l l 1 l l l ll I l l l IIIIIIIJII Aug.24,1943. "QIBURCH l 2,327,496

nl{ETHOD OF AND APPARATUS FOR WORKING MINERAL MATERIALS ANDf THE LIKEy A Filed'nec. 3, 1940 4 sheets-sheet 4 .Y K- Y INVEN-Ton CHARLES J. BURCH K BY ATTORNEY Patented Aug. 24, '1943 BIETHOD OF APPARATUS I'OR WORK- ING MINERAL MATERIALS AND THE Charles J. Burch, Kenmore, N. Y., assignor to The Linde Air Products Company, a corporanon or om@ Application December 3, 1940, Serial No. 368,2@

20 (Cl. 25E-1.8i)

The invention -relates to a method of and appa# ratus for thermally working mineral materials and the like, such as by piercing, cutting, or grooving. More particularly, the invention relates to such' a method and apparatus whereby deep holes for blasting and the like :may be pierced in mineral materials which have the property of melting under the action of intense localized heat. Some examples of mineral inaterials and the like wluch have been worked successively by means of the method and apparatus oi the present invention are iron ore, Portland cement concrete, conglomerate copper ore, Gabbro trap rock, granite, and retracto-ries such as common brick.

Piercing' or otherwise working mineral materials and the like, as carried out in quarrying, mining, and similar operations, usually is accomplished by mechanical means, such as pneumatic drills, saws, or ehisels, citen aided by explosives such as dynamite. Such mechanical operations are slow and, in the case oi pneumatic drilling of blasting holes in particular, reduire an investment in a large number of drill bits which must be resharpened frequently. Moreover, the greater the hardness and abrasiveness of the material to be worked, the greater'is the cost and t1 e slower is the rate of mechanical working.

Although the thermal working of mineral materials and the like which melt under the action of intense localized heat has been known heretofore-for example, as disclosed in the copending patent application, Serial No. 268,634 of R. B. Aitchison, C. W'. Swartout, and V. C. "Williams, filed April i8, w3c-such operations have not been wholly successful commercially for piercing blast holes of suicient depth and smoothness to meet the requirements` of mines and quarries. The failure of previously known methods to produce completely successful hole piercing may be attributed primarily to the difficulty of continuously removing the melted material or slag from the hole as the depth of the hole being pierced increases. Attempts to remove the slag in the uid condition from the hole, as by a blast of' air, have been unsuccessful after the depth oi the hole has increased beyond about two feet because the uid slag tends to solidify upon the walls of the hole as the distance from the source of heat increases.` The addition of suitable fluxes to the melted material to produce spontaneous disintegration of the solidied slag, with subsequent removal by jets of air or water, also has been attempted but has been found insufiiciently eiective to make thermal hole piercing commercially successful. Another disadvantage of prior methods oi thermally working mineral materials is `their lack of adaptabilityto automatic operation. This results from the widely variable rate of advance caused by dilculties in slag removal.

The principal object of the present invention is to provide a method of and apparatus for ther- Ymally working, as by piercing, cutting, or grooving, mineral materials and the like, which shall overcome the disadvantages of known mechanical and thermal methods discussed above.

Other objects are the provision of a novel method for thermally piercing deep, smoothlis walled holes in rneltable mineral materials and the like; the provision of such a method which shall be particularly adaptable to automatic and continuous operation; the provision of such a method which shall be operable with a speed and economy which are substantially independent of the hardness of the mineral material; and the provision of such a method in which the melted material will be continuously solidiiied and disintegrated in the hole, thereafter being removed in the disintegrated solid state.

Still another object o the invention is the provision of novel heating and slag disintegrating instrumentalities for performing the method of the invention. Other objects are the Provision of blowpipe apparatus which shall include slagdisintegrating means; which shall be sturdy, simple, and inexpensive in construction; and which shall be particularly adaptable to automatic operation Another object is to provide various forms of slag-disintegrating means.

Still another object oi the invention is the provision of suitable Iapparatus for continuously and automatically performing the method of the invention. Other objects are the provision of such apparatus whereby a heating instrumentality and slag disintegrating means may be advanced along a selected path while the slag disintegrating means is continuously actuated; whereby the heating instrumentality and slag disintegrating means may be advanced selectively either automatically or manually; and whereby a heating instrumentality of relatively great length may be advanced for substantially its full length by relatively much shorter apparatus. Another object is the provision of such apparatus, including a combination debris-collecting housing and supporting bearing for a heating instrumentality.

The above and other objects, and the novel features of the invention, will become apparent from the following description, having reference to the annexed drawings, wherein:

Fig. 1 is a longitudinal'sectional view of a blowpipe, including slag-disintegrating means, for carrying out the method of the invention;

Fig. 2 is an end elevational view of the blowl pipe of Fig, 1 as viewed from the left;

Fig. 3 is a side elevational view oi' the front portion of a blowpipe like that shown in Fig. 1, but having a modied form of slag disintegrating teeth;

Fig. 4 is a side elevational view of the front portion of a blowpipe like that shown in Fig. 1, but having another modied form of slag-disintegrating teeth; f

Fig. 5 is a side-elevational view of the front portion of a blowpipe .like that shown in Fig. 1, but having still another modied form of slagdisintegrating teeth;

Figs. 6 and 7 are perspective views of two forms of slag-disintegrating teeth;

Fig. 8 is a side elevational view, partly broken away and in section, showing apparatus set up for automatically piercing a hole in a mass of mineral material by the method of, the invention;

Figs. 9 and 10 are detailed longitudinal sectional views, parts being in elevation, of the front and rear portions, respectively, of automatic mineral working apparatus according to the invention;

Fig. 11 is a sectional view taken along the line li-II of Fig.

Fig. 12- is a sectional View taken along the line iZ-I2 of Fig. 9;

Fig. 13 is a sectional view taken along the line I3-I3 of Fig. 9;

Fig. 14 is a sectional .view taken along the line Ill-I4 of Fig. 9; and

Fig. 15 is a longitudinal sectional view of a modified form of apparatus embodying the invention.

Briefly, the method of working mineral matei rials and the like according to the present invention, as by piercing, cutting or grooving, comprises progressively and continuously applying heat to a mineral mass and melting material along a selected path to form a fluid slag, removing the uid slag from the zone of application of the heat, quenching and solidifying the fluid slag, mechanically disintegrating the quenched slag, and promptly and continuously removing the disintegrated slag from the region of disintegration.

Although some mineral materials form an easily friable slag without requiring the addition of a ux, it usually is desirable to add to the molten mineral material a ux having a composition so correlated with the composition of the material that the resulting slag will have a low melting point and will behighly fluid for removal from the zone of applicationv of heat, yet, when quenched and solidied, may be disintegrated easily. A preformed ilux may be used if desired, but it has been found most advantageous to introduce an exothermically oxidizable flux-forming powdered material (for` example, aluminum, ferro-manganese, zirconium-silicon or mixtures of such materials) continuously into the zone of `heating, where it is oxidized by oxygen gas and enters the molten slag. This latter manner of introducing flux has the advantage of releasing to the melting zone the extremely high temperature heat of oxidation of the exothermically oxidizable flux-forming material.

Thel method of the invention -Will be described more specically in connection with Figs. 1 and 2,

as the blowpipe B. Other types of heating instrumentalities, of course, may well be usedfor example, electric arc instrumentalities. One form of blowpipe B according to the invention, as shown in Fig. 1, comprises an elongated straight tubular member including a heat-producing unit, J, and rotatable slag-disintegrating means'R arranged outside of and concentric with the heat-producing unit J. The heat-producing unit J of the blowpipe,l shown by Way of example only, comprises a hexagonal tip I I rigidly connected to a rear body or header I 2 by Ameans of an oxygen gas conduit I3, which is threaded at its forward end Within a bore I4 .in the tip and at its rear end. is threaded within the front of a bore I5 in the rear body. A centrally arranged acetylene conduit IS, which ilts snugly at its forward end within a central passage in the tip II and opens to the front face Vof the tip, at its rear end is secured to an inlet nipple I'I threadedinto the rear end of the bore I5 in the rear body I2. Acetylene gas, or a suspension of flux or ux-forming powder in acetylene, thus may be conducted through the conduit I6 and discharged in a central stream from the blowpipe tip il.

Oxygen gas is admitted to the bore I5 through an inlet nipple I8, threaded into a cross bore I9 in the body l2, and passes forward through the annular space'20 between the central acetylene conduit I6 and the oxygen conduit I3 to the blowpipe tip II, Where it enters the front of the bore I4. Thence, the oxygen is discharged from the front of the tip I I through a plurality of discharge ducts 2i arranged in an annular ring around the end of the central conduit I6, and inclined forwardly towards the longitudinal axis of the blowpipe and toward one another. Thus, oxygen gas is discharged from the tip II in a plurality of small streams which intersect the central acetylene stream externally of the blowpipe and produce a combustible gas mixture which, when ignited, forms a socalled diffusion-type flame which is not susceptible to flashbacks when used in conned spaces, as in rock piercing operations. Simultaneously, any exothermically oxidizable ux-forming powder carried by the acetylene is oxidized by the oxygen stream and adds its heat to that produced by the gas mixture. The terms oxygen and acetylene are used for simplicity as representative of any suitable oxidizing gas and any suitable fuel-gas respectively,

The slag-disintegrating means R comprises an annular re'amer tube or sleeve 22 which is sleeved over and surrounds the conduits I3 and I6 of the name-producing unit in spaced relation to the conduit. I 3 to provide an annular cooling fluid passage 23. The sleeve 22 is journalled .at its rear for rotation within a counterbore 24 in the front of the rear body I2; and at the front the sleeve 22 is supported by the tip II in fluid-tight relation thereto by a cone seat 25 at the rear of the tip cooperating with the bevelled front end of the sleeve 22. A coil spring 26 in the counterbore 24 is compressed between the bottom surface of the counterbore and an annular flanged thrust washer 21, which in turn bears against the rear end of the sleeve 22, thus resiliently urging the forward end of the sleeve 22 against the seat 25 with a light pressure and maintaining a tight joint while the sleeve 22 rotates. A fluid, such as Water, for

cooling the blowpipe. and lfor quenching and electing slag, is supplied to the annular passage 23 through an inletA nipple 28 which opens into the counterbore 24 in back of the rear end of the sleeve 22. Leakage of water from the front of the counterbore 24 is prevented by means of suitable packing material 29, which is compressedv against both the front face of the rear body I2 and the external surface of the sleeve 22 by means of an internally threaded gland nut threaded over the front of the body I2 and held in xed position by means of a lock nut 3 i.

For a short portion of its length adjacent to its rear end the hexagonal tip il is cylindrical in shape, as at 32, thus forming a bevelled shoulder et at each corner oi the tip.

A. plurality ci' generally V-shaped liquid discharge passages or ports 34 are arranged in a' ring in the tip il, one leg of each port being inclined at an angle outwardly toward the rear end of the blowpipe and having an external discharge oriilce on the bevelled shoulder 33 of the tip. The other leg of each liquid discharge port all extends substantially parallel to the blowpipe axis and. communicates with an annular distributing chamber te liorn'ied between the conduit it and the wall oi 'a counterbore in the iront oi' the sleeve 22.

The sleeve it carries adjacent toits forward end, and 'as close as possible to the front of the tip l l, four equi-spaced radially outstanding slagdisintegrating reamer 'teeth di, which may be welded o1: otherwise secured to the sleeve 122. In the particular example shown in Fig. l, each of the teeth ill comprisesa relatively long and narrow straight steel base member 33 of rectangular cross section, arranged parallel to the longitudinal axis ci the blowpipe, and carrying a fusion deposited layer oi an intensely hard andwear-resistant facing material such as Haynes Stellite alloy (a. cobalt-chromium-tungsten alloy) upon the surfaces subject to the greatest abrasionin service, such as the top surfaces of the teeth. The blowpipe is similar in some respects to the blowpipes described and claimed in Patent No. 2,236,191, issued June 16, 1942, to R. B. Aitchison,

C. J. Burch, and C. W. Swartout.

When performing the method of the invention, as applied to hole piercing, with the blowpipe of Figs. 1 and 2, Vacetylene gas, or a suspension of powdered preformed ilux or an exothermically oxidizable ux-i'orming substance in acetylene gas, is discharged in a. central stream from the tip il through the front of the conduit I6 and is intimately mixed externally of the blowpipe with the converging oxygen gas jets issuing from the ducts 2|. The combustible gas mixture thus formed is ignited and the blowpipe is held with the tip Il close to the face of the mineral mass to be pierced until material starts to melt under the iniluence of the llame and a shallow crater forms as the loosened slag flows away under the inuence of gravity and the gas pressure. As the depth of the crater increases, the blowpipe is advanced into the hole to heat continuously the material at the bottom, and the molten slag flows rearwardly. Meanwhile, the reamer sleeve 22 is continuously rotated relatively to the heat-producing unit J, either manually with the spokes 39 providing a hand hold, or automatically as will be described hereinafter. The sleeve 22 is rotated preferably in a direction which will cause the tip Il to be tightened on the threads at the front of the conduit I3.` Thus, for example, if the tip I I must be tightened on the conduit Il with a clockwise motion, as seen in Fig. 2, the

reamer tube 22 should be rotated clockwise as viewed from the tip end in Fig. 2.

Cooling water which Eis passed through the small particles, which are then elected from the hole by the force of a owing stream oi ejection huid, including the gaseous products of combustion, the steam resulting from the slagquenching operation, and the quenching water streams discharged from the ports 3d. In addition, the teeth 3l ream the walls oi the hole to make them smooth and provide a hole oi unhform diameter.

The iront portions only of three modified forms oi' blowpdpes are shown in elevation in Figs. 3, 4, and li, inasmuch as the tip and the rear body of each, and the manner of connection of the various conduits to the tip and'the rear body, are the same as in the blow'pipe of Figs. l and 2. As shown in Fig. 3, a rotatable sleeve tt carries adjacent to its forward end. and `lust in back of the tip 4i, a plurality of reamer teeth d2, preferably four spaced at quarter points around the periphery of the sleeve, which are of generally rectangular cross section and relatively great length as compared to the teeth of Fig. 1. Each tooth consists o1 a relatively short front portion 43 inclined forwardly along the surface ci the sleeve 40 in the direction of rotation, preferably at a rake angle of about 15 with respect to the` 'l longer straight portion 44 extending rearwardly from its junction with the front portion 43 substantially parallel to the longitudinal blowpipe axis. Inclination of the front portion of the teeth 42 in the direction of rotation causes the teeth actually to bite into the slag and move the slag rearwardly; and the great overall length of the teeth provides for complete, eillcient and rapid disintegration of the quenched slag. In the modification of Fig. 3, streams of quenching fluid, such as water, are discharged from the ports 45 in the tip, as in the blowpipe of Fig. 1. In addition, however,` the sleeve 40 is provided with a plurality of auxiliary radial fluid discharge ports 46,v one being located midway between each pair of teeth 42 approximately on a line with the junctions of the inclined portions 43 and the` straight portions 44. Fluid, such as water, is discharged from the ports 46 and provides forv a continuous quenching action on the slag over a much longer distance of travel than is possible with the blowpipe of Fig. 1, thereby producing more complete solidiiication of the slag before it passes beyond the zone of action of the teeth 42. Moreover, the iluid leaving the ports 46 has an advantageous cooling action on the reamer teeth'42, thus protecting them from possible destruction.

As shown in Fig. 4, the rotatable sleeve 48 carries adjacent to its forward end a plurality of reamer teeth 49, preferably four, which are inclined forwardly in the direction oi' rotation at a rake angle with respect to the projection o1' the longitudinal axis of the sleeve 08 upon the outer surface of the sleeve. As in the blowpipe of Fig. 3, inclination of the teeth forwardly in the direction of rotation causes them to bite into the slag and tends to move the slag rearwardly. Although teeth set at a rake angle up to 45 may be advantageous, the rake angle preferably should be less than 30. As shown in Fig. 1, the teeth i9 are set at a rake angle of about 15, which has been found most satisfactory for slag disintegration with the least interference with slag removal from a hole.

Fig. 5 shows a blowpipe with two generally helix-shaped teeth 50, each tooth extending at least half-way around the sleeve' 5l and being inclined forwardly in the direction of rotation. Such teeth not only break up the solidified slalg but assist in conveying the slag rearwardly towards the mouth of the hole being pierced. A single tooth extending at least once completely around the sleeve 5i also may be used.

As mentioned in connection with Fig. 1, the surfaces of greatest wear on reamer teeth may be protected by an extremely hard wear-resistant material carried by a relatively softer base metal. As also described in connection with Fig. 1, protection may be accomplished by melting and depositing a layer of Haynes Stellite alloy, or a similar material, which permits teeth to be rebuilt easily andA quickly to gauge when worn. Figs. 6 and 7 show two other ways of protecting reamer teeth against excessive wear, which are particularly applicable to straight teeth. In Fig. 6, the top of a straight tooth 52 is slotted 1ongitudinally from the top through about half its thickness and between its sides. A preformed insert 53 of tungsten carbide or a similar preformed wear-resisting material, then is inserted into the slot with its top edge projecting above the top surface of the tooth 52 and is brazed or otherwise secured finmly in place. Inserts of tungsten carbide or the like are used in a slightly different way in the tooth 54 of Fig. 7, wherein a shallow longitudinal groove is formed only in that upper corner of the tooth which includes the leading edge during rotation of the sleeve. An insert 55 of tungsten carbide or the like then is laid flat and is brazed or otherwiselsecured in place in the corner groove with one of its sides facing in the direction of rotation. In both Figs. 6 and 7, it is most desirable that the insert of tungsten carbide'or the like have a rounded front edge which projects slightly beyond the forward end of the tooth base to reduce wear on the front of the tooth.

A few of the requirements for reamer teeth in general may well be considered. First, 'the height of the individual reamer teeth preferably should be between 25% and 50% of the'outside diameter of the reamer sleeve to provide a reamed hole of a diameter between 50% and 100% greater than the diameter of thereamer sleeve. If the reamed hole has a diameter less than 150% of the reamer sleeve outside diameter, inadequate space for debris ejection usually is provided. Second, the length of the reamer teeth preferably should not be less than the diameter of the reamed hole to insure the production of a straight smooth-walled hole. The longer the teeth are, the more nearly straight the hole is and the greater the footage which can be drilled before the gauge is lost. For practical purposes, however, a length of tooth greater than about four times the diameter of acca-see the hole being reamed usually is not advantageous. Third, the reamer teeth should start as near the forward end of the blowpipe as is possible without interfering with the melting and slag quenching functions of the blowpipe. Fourth, the number of teeth is preferably four, although any number could be used. The greater the number of teeth, the more surely a round hole is produced, but the less the area available for ejection of debris from the hole. s-

As shown in Fig. 8, apparatus for working mineral materials and the like, as for piercing holes automatically according to the method ,of the invention, comprises a. long straight heating instrumentality, such as the blowpipe B described in connection with Fig. 1 (but without the spokes 39), carried by a carriage C which moves longitudinally over a support comprising derbis-removal conduit D having suitable ways or tracks on its upper surface for the carriage C to traverse, and having suitable ways on its bottom surface engaged by a sliding trunnion A which is pviotally mounted in a pivoted socket member of an adjustable tripod T. As described in connection with Fig. l, the blowpipe B comprises a non-rotatable heat-producing unit J which is supplied from suitable sources with combustionsupporting gas and fuel gas, such as oxygen and acetylene, respectively, through the hose connections O and N, respectively, and is adapted to produce an intense oxyacetylene flame, preferably of the externally-mixed or diffusion type, at its forward end. The blowpipe B also comprises rotatable slag-disintegrating means R, including aV sleeve 22 surrounding and spaced from the heatproducing unit J, and carrying adjacent to its forward end behind a tip ll projecting reamer teeth 37. Cooling water for the blowpipe is supplied through the conduit W and flows in the annular space between the heat-producing unit J and the rotatable sleeve 22 to the forward end of the blowpipe, where it is discharged in a. rearward direction. A powder dispenser P of any desired type, such as that described and claimed in application Serial No. 364,958 led by C. J. Burch, and W. C. Edwards on November 9, 1940, is in,- terposed in the acetylene conduit N and permits suitable powdered flux or flux-forming material to be suspended in the acetylene gas supplied to the blowpipe. If the character of the mineral material to be worked is such that no flux is required, the. dispenser P may be left empty or removed.

In automatically performing the mineral working method of the invention, as applied to the piercing of a blast hole G in a mass M of rock or the like, the housing H of the debrisremoval conduit D is positioned close to the rock face, the carriage C is adjusted to its rearmost position on its support, and the blowpipe B is adjusted on the carriage C to bring the tip Il suilciently close to the rock face that the intense externally mixed oxyacetylene llame and the flux or flux-forming powder impinge against the rock. As in manual operation, material then melts and produces a shallow crater in the rock as the molten slag flows out under the influence of gravity and the gas pressure. As the depth of the hole increases, the carriage C is advanced steadily over its support by a feed screw, which may be either hand-driven or motor-driven, thus maintaining the tip IlV of the blowpipe B spaced properly with respect to the advancing bottom face of the hole. Concurrently, the rotatable sleeve 22 and reamer teeth 3l of the blowpipe are rotated continuously by a suitable motor drive `mechanism carried by the carriage C. While the sleeve 22 is rotating, the heat-producing unit J, including the rear body l2 and the tip il, is held against rotation by the weight of the conduits W, O, and N. Other means, of cggrse, may be used to prevent rotation-of the heat-producing unit J.

The flame produced at the forward end of the blowpipe B continues to melt of! mineral material progressively from the bottom or forward face of the hole. The molten material then flows rearwardly from the zone of flame application in a highly uid condition until it is brought into contact with the streams of cooling water discharged from the blowpipe and is quenched and' solidified. As fast as it is produced, the solidied slag, which is quite friable, is continuously disintegrated by tlie rotating reamer teeth 31 carried by the sleeve 22 adjacent to its forward end. Disintegrated slag particles continuously are driven rearwardly toward the mouth of the hole G by the force of the gaseous products of combustion and the steam formed by the quenching operation, as well as by the propelling action of the rearwardly directed water streams themselves. Afterleaving the mouth of the hole G, the disintegrated slag particles, the gaseous products of combustion, the steam, and the discharged water are collected for the most part in the housing H and pass through the debrisremoval conduit D, which is connected by a flexible hose K to a primary separator S, wherein most of the solid slag particles and water are separated from the entraining gases and discharged from the bottom of the separator. The gaseous products of combustion and the steam then pass through a bag filter F, of well-known construction, where any entrained solid particles are collected. The remaining gases then are dis-y charged from the top of the exhaust fan E to the atmosphere.

From Fig. 8 it may be seen that 'the sliding trunnion A is so pivoted to the tripod T, and' the legs of the tripod T are so pivoted and so adjustable as to length, that holes may be pierced at any desired angle to the face of a mineral mass M. Furthermore, the blowpipe driving apparatus may be underslung from the tripod T in inverted position whenever holes are to be pierced in a mineral mass close to the floor level.

Figs. 9 to 14, inclusive, show in detail the construction of the novel apparatus for automatically performing the method of the invention, particularly for manipulating-a heating and slagbreaking instrumentality, such as the blowpipe of the invention, for the piercing of holes in mineral materials and the like. The apparatus includes mechanism for advancing the rock piercing blowpipe B (shown in part) along a selected path to form a hole, and mechanism for continuously rotating the rotatable sleeve 22 of the blowpipe, carried upon a support of any suitable character. As shown in Fig. 9, the support includes a sliding trunnion A, of Well-known construction, comprising a cone 56 adapted to be Aswiveled in the top of an adjustable tripod T (such as shown in Fig. 8), suitable clamping jaws 51, and an adjustingv nut 58 whereby the jaws 51 may be engaged with or disengaged from longitudinally-extending ways 59 welded to the lower portion of a debris-removal conduit D to permit sliding adjustment of the conduit D in the trunnion A. Two long longitudinally-extending channel-shaped ways or tracks 60 are welded to opposite sides of the1 upper portion of the debris-removal conduit D with the open sides of the generally U-shaped channels facing one another.` v

The mechanism for advancing the blowpipe B over the support comprises a carriage C for the blowpipe, including two longitudinally-extending L-shaped slides 6l (see Fig. 12) which flt slidingly within the channels of the tracks 60. A feed screw 62, which is journalled at its forward end in a pillow block 66 welded to the top of the conduit D between the two tracks 66, and at its rear end is journalled in a pillow block 64 bolted to a bracket 65 secured to the tracks 66 adjacent to the rear end of the latter, drives the carriage C along the tracks 61|` by engaging an adjustable split traveling nut 66 secured, as by welding, to the two slides 6I.

The mechanism for selectively driving the feed screw 62 either manually or automatically is en-l the debris-removal conduit D and to the portions of the two tracks 60 which overhang the bend 69. The rear portion of the feed screw 624 comprises a journal 10 which is journalled in the pillow block 64 and passes through the front and rear walls of the housing 61. A hand crank 1l is keyed on the rear end of the journal 10 to permit hand operation of the feed screw 62. Longitudinal movement of the feed screw 62 in the pillow blocks 63 and 64 is prevented by a collar 12 secured to the journal 10 just in front of the pillow block 64 by suitable set screws.

Automatic operation of the feed screw 62 may be obtained, if desired, by means of anelectric motor Ms suspended from the bracket 65 by means of suitable bolts threaded into a projecting boss at the top of the motor housing. The motor Ms drives a suitable speed-reducing gear unit 13. including a shaft 14 carrying a worm 15 meshed with a worm gear 16, which is mounted for free rotation upon the journal 10 of the feed screw 62. An eccentric arm 11 is keyed to the journal 10 of the feed screw 62 in back of the worm gear 16 and carries adjacent to its outer end a longitudinally movable connecting pin 18 having an enlarged head 19 riding within a cavity 8l in the arm 11. The head 19 is adapted to be inserted Within any one of the sockets 82 of the worm gear 16 and maintained in interlocking position by a coil spring 83 in the cavity 8|. When the worm gear 16 and the eccentric arm 11 are interlocked by the connecting pin 18, the motor Ms will cause the feed screw 62 to rotate at a speed which may be regulated by a rheostat`84.

When manual operation of the feed screw 62 is desired, as when starting the piercing of a hole, the motor drive may be disengaged from the feed screw by drawing the spring-pressed connecting pin 18 rearwardly to carry the enlarged head 19 from the socket 82 of the worm gear 16 back into the cavity 8| of the eccentric arm 11. A stop pin 85, projecting laterally from the connecting pin 18. at the same time is carried rearwardly from a groove 86 in the rear side of the arm 11 to the rearface of the eccentric arm, whereupon the connecting pin then may be maintained in withdrawn position simply by turning-it until the stop pin 66 abuts against the rear face of the eccentric arm 11. A circular shield 81 on the outside of the housing 61, through which the eccentrically arranged connecting pin 'I8 passes, isfixed to the journal I in back of the eccentric arm 'II and rotates with the drive screw 62 close to the outer rear wall of the housing to seal the large aperture 88 against the entrance of dirt which might foul the motor drive.

Details ofthe carriageC for the rock piercing blowpipe B are shown infFigs. 9, l2, and 13. The housing 9B of Welded sheet. steel, which carries downwardly-extending L-shaped slides 6i and a traveling nut 66, as described previously, also includes a blowpipe-driving electric motor Mb and a speed reduction unit 9i having a horizontal shaft 92 carrying a spricket 93, which is connected to another larger sprocket gli adjacent to the top of the carriage C by a sprocket chain @5. The large sprocket 913 is mounted upon, a short hollow shaft '95 by means of set screws, and the hollow shaft 95 in turn is mounted for rotation in ball bearings Sl and 98 disposed in bearing cups gli and` It@ arranged back-to-back and connected to the front and rear walls of the housing 9d, respectively, as by welding. The bearings Si and 98 are retained in the bearing cups stl and wil by suitable retaining plates tilt and w3, respectively, bolted to the rims of the cups. A steel spacing ring HM is carried by the shaft 96 between the hub of the sprocket 9&5 and the innerrace of the bearing Si? to maintain the parts in spaced relation to one another. At its forward end, the

hollow shaft Sii is provided with a flange ii K which fits within a bore of the retaining plate i632 and bears against the inner race of the bearing el; and at its opposite rear end the hollow shaft SG, which projects rearwardly through a bore in the retaining plate i 03, is externally threaded for engagement with a chuck il having serrated movable jaws lill gripping the rotatable reamer sleeve 22 of the blowpipe B (shown in part), which extends through the hollow shaft 96 in SpaCed relation to its inner wall.

Operation of the motor Mb causes the hollow shaft Strand the chuck IUS to revolve, thus rotating the reamer sleeve 22 independently of the heat-producing unit J of the blowpipe. Rotation of the 'reamer sleeve 22, ofcourse, revolves the outstanding reamer teeth 3l carried adjacent to the forward end of the blowpipe, with resulting disintegration of any solidified friable slag brought into contact with the teeth.

The blowpipe B may be adjusted longitudinally with respect to the carriage C simply by unscrewing the bolts I 0B of the chuck I 06 to withdraw the jaws I ill from engagement with the reamer sleeve 22. Separation of the two jaws Ill'l from the sleeve 22 is assisted by the two resilient hairpin springs Ig connecting the jaws III'I together. When it is desired to insert or remove the forward end of the blow pipe through the chuck IGS, the

bolts IDB are fully withdrawn from the jaws ID'I and the latter removed from the chuck to provide a passage of suicient size to accomodate the reamer teeth 3l.

The position of the whole carriage C also may be quickly adjusted in the tracks 60 with respect to the feedscrew 62 by disengaging from the feed screw the split traveling nut unit t6, shown in detail in Fig. 12. 'Ihe traveling nut unit 66 comprises two half-nut blocks Hi and H2 arranged for sliding movement toward and away from one another in a four-sided rectangular housing H3 secured within a saddle formed in the two L-shaped slides 6I, as by welded joints formed between the slides and the bottom and side walls of the housing H3. The

half-nut blocks IH and H2 are provided with axially aligned internally threaded bores I I4 and H5 above the feed screw meshingthreads H8 and II'I, one bore having left-hand threads and the other bore having righthand threads. .A unitary shaft H8 extends through the two bores Ht and vH5 and is fixed in position by means of a retaining saddle HS secured to the upper wall of the housing H3 and riding in an annular centrally arranged groove |20 on the shaft. The two portions of the shaft H8 within the halfnut blocks IH and H2 are threaded to cooperate with the threads in the two bores -I I4 and H5. Turning one or both of the two handwheels Ii and I22 on the ends of the shaft H8 in one direction will cause the two half-nut blocks Hl and H2 to move away from one another and disengage their threads HB and H1 from the feed screw 62; and turning one or both of the hand-wheels iZI and I22 in the opposite direction will bring the twohalf-nut blocks III and H2 back into engagement with the feed screw 62. With the traveling nut unit 69 disengaged from the feed screw 62, the carriage C may be moved by hand longitudinally in the tracks 6U over the carriage support, for properly adjusting the position of the blowpipe B with respect tothe mineral mass to be pierced.

'Ihe provisions for independent adjustment of the blowpipe B and the carriage C relatively to one another, and for independent adjustment of the carriage C over the tracks Si) relatively to the feed screw 62 are particularly valuable because they permit a hole of very great depth to be pierced with blowpipe-driving apparatus considerablyshorter than the depth of the hole to be pierced. For example, a blowpipe B of approximately twice the length of the feed screw 52 may be engaged by the chuck |06 approxi-` mately at its mid-point when the carriage C is drawn as far as possible toward the rear of the apparatus. After the carriage C has advanced for the full length of the feed screw 62, the chuck EN may be disengaged from the blowpipe in the manner described above, and the split traveling nut unit 56 may be disengaged from the feed screw S2. The carriage C then is quickly returned by hand to its rearmost position, while the blowpipe B is held at its farthest point of advance. Thereafter the chuck IUS is again brought into engagement with the blowpipe B, the traveling nut unit 66 is again brought into engagement with the feed screw 62, and the carriage C carrying the blowpipe B again may be advanced continuously to increase the depth of the hole.`

Disposal of the debris' .produced during the piercing of a hole, comprising disintegrated slag,

' the exhaust gases and fumes, and the steam and water discharged from the mouth of the hole, is accomplished by positioning the housing H of the debris-removal conduit D adjacent to the mouth of the hole being pierced, and applying a suction through a hose K connected to an exhaust fan E, in the manner shown in Fig. 8. As shown in Fig. 9, an annular water-spray ring i213 is fixed to the rim at the 'front of the housing H and arranged to discharge sprays of water rearwardly into the interior of the housing to insure the thorough moistening of the debris. l

as well as to keep clean the walls of the conduit D and expedite the passage of the debris. A water-spray nozzle I25 projects into an elbow H25 in the conduit D between the inclined neck I2? and the horizontal portion |28, to propel the particles of debris through the conduit and keep thewallsclean. The'sprayring |23 and the nomic Ill are connected into a single water supply conduit |23.

The housing H includes arearwarfdly projecting tubular member |33. forming a r w 1 |3| axially aligned with the hollow shaft II. throuh which the blowpipe B operates. 'Ihe diameter of the passage |3| is sumcient to permit lthe Projecting reamer teeth 31 on the forward end of the reamer sleeve 22 to pass easily. In order to prevent the escape of debris through the passage |3| to the atmosphere adjacent to the scene of operation. and in order to adequately support and guide the blowpipe B, a. combined front bearing and closure |32 is provided,v as shown in detail in Fig. 14. 'I'he bearing and closure |32 comprises two arcuate half-sections |33 and |34, hinged to the rear end of the tubular member |30 `by means of bolts |35 and' |38. Each of the half-sections |33 and |34, when in operative position, ilts closely about the surface of the blowpipe B andis secured in position by means of a latch |31 comprising a bolt and pressure plate at the top of the tubular member |30.-

Preferably, the inner arcuate surfaces of the half-sections |33 and |34 are provided with a suitable wear-resistant material such as Haynes Stellite alloy, for resisting the abrasive action of the rotating reamer sleeve 22. In order to insert or remove the blowpipe B through the housing H, it is only necessary to loosen thelatch |31, swing the two arcuate half-sections |33 and |34 apart, and pass the blowpipe through the passage 3|.

The construction and arrangement of the debris-removal conduit D are described and claimed in the copending application, Serial No. 369,002 iled by GeorgeH4Smith and Charles J. Burch, December 7, 1940.

Fig. 15 shows an electric arc apparatus for performing the method of the invention. The construction is very similar to the blowpipe of Fig. 1, except that the central tube I6 has been replaced by two electric cables IB connected at their forward ends to two tungsten electrodes I1' projecting forwardly through' the front of the tip Il?, and surrounded by electrical insulation I8'. 'I'he cables I6' extend rearwardly to and through a rear body similar to that of Fig. 1, and may be connected to a suitable source of electricity. 'Ihe arc formed between the electrod is equivalent to an oxyacetylene ilame in the method of the invention.

As previously mentioned, minerals and mineral-like materials of many different kinds may he Worked by the process and apparatus of the present invention. As an example, a hole 78 inches deep and 1% inches in diameter was pierced at a slight angle upwardly from the horizontal by the method and apparatus of the invention in Minnesota Soudan iron ore, principally an extremely hard and dense iron oxide, at a rate of 31/2 inches per minute, using a flux-forming powder mixture consisting of 50% aluminumv and 50% ferro-manganese. In a total of 52 feet of drilling, using the saine flux-forming mixture, the rate of drilling varied between 2 and 31/2 inches per minute on different blasting holes.

In contrast, pneumatic drilling of Soudan iron ore, using regular drill steel bits proceeded at an average rate of less than 1/2 inch per minute, actualdrilling time, over a total oi' 19,222 feet'of drilling, according to the U. S. Bureau of Mines- Information Circular 6911. According to the same circular, moreover, each bit averaged only 6 inches of drilling before ng was necvIllrom the foregoing, it is evident that there have been provided a novel and valuable method of and apparatus for thermally working mineral Y materials and the like, and particularly farthermaliy piercing holes in such materials. Although the invention has been described by way of example in connection with the piercing of holes, however,'it is to be understood that the principles may be applied in other ways, and changes in construction of the apparatus and application of the method may be made by those skilled in the art, without departing from the spirit oi' the invention, as deilned by the appended claims.

What is claimed is:

1. Method of working mineral materials and the like which comprises progressively melting material along a selected path and forming a fluid slag. quenching and solidifying the slag so formed, mechanically disintegrating the quenched slag, and removing the disintegrated slag from the region of disintegration.

2. Method oi.' working mineral materials and the like which comprises progressively melting material along a selected path, introducing into the molten material a flux adapted to form therewith a slag which, when solidified, may be disintegrated easily, quenching and solidifying the slag so formed, mechanically disintegrating the quenched slag, and removing the disintegrated slag from the region of distintegration.

3. Method of piercing holes in mineral materials and the like which comprises progressively melting material at a'selected zone and forming a uid slag, advancing the melting zone into such material to form a hole, quenching and solidifying the fluid slag in such hole, mechanically disintegrating the quenched slag in such hole, and removing the disintegrated slag from such hole.

4. Method of piercing holes in mineral materials and the like which comprises progressively applying a ame to such material to melt the same and form a fluid slag, advancing the flame into such material to form a hole, injecting water into Such hole in back of the region of the flame to quench and solidify the slag, mechanically dlsintegrating the quenched slag in such hole, and ejecting the disintegrated slag from such hole with a llowing stream of ejection fluid.

5. Method of piercing holes in mineral materials and the like which comprises progressively melting material at a selected zone and forming a fluid slag, advancing such melting zone into such material to form a hole, quenching and solidifying the fluid slag in such hole, mechanically disintegrating the quenched slag in such hole, reaming the Walls of such hole, and removing the disintegrated slag from such hole.

6. Apparatus for 'thermally working mineral materials and the like comprising means for producing intense localized heat whereby to melt portions of such mineral material; means for bringing cooling fluid into contact with such melted portions to quench and solidify the same; and means for disintegrating such quenched material by physical impact therewith.

7. Apparatus for working mineral materials and lthe like comprising an elongated flame producing unit adapted to provide intense heat adjacent to the front thereof; a sleeve rotatably journalled von said unit:` and means carried by said sleeve adjacent to the front thereof for disintegrating slag or the like by physical impact therewith.

8. Apparatus as claimed in claim '7 wherein said means for disintegrating slag or the like comprises a plurality of teeth extending substantially parallel to the longitudinal axis of said sleeve.

9. Apparatus as claimed in claim 7, wherein said means for disintegrating slag` or the like comprises a plurality of teeth inclined along the outer surface of said sleeve with respect to the projection of the longitudinal axis of said sleeve upon such outer surface.

10. Apparatus as claimed in claim 7 wherein said means for disintegrating slag or the like comprises 'a plurality of teeth, each comprising a forward portion inclined along the outer surface of said sleeve with respect to the projection of the` longitudinal axis of said sleeve upon such outer surface, and a rear port/ion' extending substantially parallel to the longitudinal axis of said sleeve.

11. Apparatus as claimed in claim 7 wherein said means for disintegrating slag or the like comprises one or more teeth carried. by said sleeve.

l2. A blowpipe comprising a name-producing unit including a tip, a body, and conduit means rigidly connecting said tip to said body; a rotatable sleeve arranged over said conduit means and journalled in said body for rotation relative to said flame-producing unit, said sleeve being supported at its front by said tip; and means carried by said sleeve adjacent to its forward end for disintegrating slag and the like by physical impact therewith.

13. A blowpipe comprising a flame-producing unit including a tip, a body, and conduit means rigidly connecting said tip to said body; a, rotatable sleeve arranged over said conduit means in spaced relation thereto and journalled in said body for rotation relative to said flame-producing unit, said sleeve being supported at its front by said tip in substantially fluid-tight relation thereto; means urging said tip and said sleeve into substantially iiuid-tight relation with each other; means carried by said sleeve adjacent to its forward end for disintegrating slag and the like by physical impact therewith; and said blowpipe having passage means adjacent to the forward end thereof communicating with the space between said sleeve and said conduit means and opening to the external surface of said blowpipe.

14. A blowpipe comprising a flame-producing unit including a tip, a body, and conduit means rigidly connecting said tip to said body; a rotatable sleeve arranged over said Conduit means in spaced relation thereto and journalled in said body for rotation relative to said flame-producing unit, said sleeve being supported at its front by said tip; means carried by said sleeve adjacent to its forward end for disintegrating slag or the like by physical impact therewith; and a plurality of generally V-shaped passages in said tip, each passage comprising a leg inclined outwardly toward the rear of said blowpipe having a discharge opening on the outside of said tip, and .a leg establishing communication between said first-named leg and the space between said sleeve and said conduit means.

l5. A blowpipe having a. flame-producing unit; a sleeve rotatably journalled on said unit; a plurality of generally longitudinally extending circumferentially spaced slag-disintegrating means carried by saidv sleeve adjacent to its forward end; passage means for discharging a cooling medium from saidrblowpipe ahead of said slag-disintegrating means; and said sleeve having passage means through the wall thereof between said slag-disintegrating means and` intermediate the ends of the latter for discharging a cooling medium from said blowpipe.

16. Apparatus for piercing holes in a mass of mineral material or the like comprising, in combination, an elongated flame-producing unit adapted to heat and melt portions of such material; means for discharging a fluid adjacent to the, forward end of said unit to quench and solidify such melted material; a device rotatably journalled on said unit; means carried by said device adjacent to the forward end thereof for disintegrating such solidified material by physical impact therewith; means for advancing both said unit and said device into such mass to form a hole; and means for rotating said device.

17. Apparatus for piercinga hole in a mass of mineral material or the like comprising, in combination, an elongated flame-producing unit; a device rotatably mounted on said unit; tooth means carried by said device and projecting therefrom adjacent to the forward end thereof; means for advancing said unit and said device and the tooth means carried by the latter into such mass to form a hole; and means for rotating said device during the operation of such advancing means.

18. Apparatus for producing holes in mineral materials and the like,hav'ing an elongated flameproducing unit adapted to provide an intense heating ame adjacent to one end thereof; a sleeve rotatably journalled on said unit; passage means for discharging water from said apparatus adjacent to said end of said llame-producing unit to quench and solidify molten slag; and

means carried by said sleeve adjacent to said passage means for disintegrating quenched slag by physical impact therewith.

19. A blowpipe comprising a name-producing unit including a tip, a body, and conduit means rigidly connecting said tip to said body; a rotatable sleeve arranged over said conduit means and journalled in said body for rotation relatively to said flame-producing unit, said sleeve being supported at its front by said tip; spring means carried by said body resiliently urging said sleeve against said tip; and means carried by said sleeve adjacent to the front thereof for disintegrating slag and the like by physical impact therewith.

20. A mineral piercing blowpipe comprising an elongated straight tubular member having front and rear ends, said tubular member being adapted to provide a iiame adjacent to said front end; and tooth means projecting from said tubular member adjacent to said front end constructed and arranged for disintegrating mineral material loosened by such llame. y

CHARLES J. BURCH. 

